The antecedents of man the manipulator

Abstract

Four individuals of each of ten Primates species were presented with a length of nylon rope and their manipulative responses recorded in detail. The 172 specific types of actions observed were consolidated into 69 generic categories and then further taxonomized into Primary actions, in which the rope was directly acted upon, of two types depending on whether the rope was grasped or not, and Secondary actions, in which the rope was manipulated with respect to objects, with two types depending upon whether the second object was a part of the body or part of the environment. The ten species tended to fall into two groups: (1) the lemurs, highly arboreal monkeys, and gibbons, and (2) a less arboreal monkey and the great apes. The latter group generally engaged in more different types of actions, more secondary actions, more intentional contacts, more action away from the body, more proximal body contact, and more species-unique actions. It was inferred from these and other data that the antecedents of Man were more object-interested and manipulative than the precursors of nonhuman Primates at comparable levels of brain size development.